000
AXNT20 KNHC 282239
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Wed Jul 28 2021

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through 
2230 UTC.

...TROPICAL WAVES...

An Atlantic tropical wave is along 25W from 18N southward, moving
W near 15 kt. Scattered moderate to isolated strong convection is
evident from 06n to 09N between 21W and 29W.

Another Atlantic tropical wave is along 43W from 19N southward, 
moving W 20 to 25 kt. Satellite imagery suggest that this wave is
surrounding by a broad area of Saharan air that is inhibiting 
deep convection.

A tropical wave was introduced to the analysis over the far 
eastern Caribbean along 62W south of 16N. This tropical wave is 
associated with an upper low centered to its northwest near 
18N65W. Divergent flow aloft on the southeast side of the upper 
low is supporting scattered moderate convection east of the wave 
axis, covering most of the Windward Islands. 

Another Caribbean tropical wave extends from eastern Cuba through
Jamaica to eastern Panama, moving W at 20-25 kt. No deep 
convection is associated with this wave as dry stable air is 
immediately located behind this wave across the eastern 
Caribbean.

...MONSOON TROUGH/ITCZ...
A monsoon trough extends across the coast of Africa near the
Mauritania-Senegal border to 05N40W. The ITCZ then continues from
05N45W to the coast of French Guiana at 05N51W. Beyond convection
described above associated with the tropical waves, the Saharan 
Air Layer is limiting any further convection.

...GULF OF MEXICO...

A surface trough reaches from the mouth of the Mississippi River 
to near 24N94W. Scattered showers and a few thunderstorms are 
noted within 60 nm either side of this rough from 23N to 26N. No 
other significant convection is evident across the Gulf. Light to 
gentle breezes and slight seas are noted across the basin.

For the forecast, the trough will remain over the NW Gulf on Thu 
while gradually weakening. In its wake, the Atlantic high pressure
will begin to build westward into the Gulf waters on Thu, with a 
high pressure cell developing over the eastern Gulf. This system 
will move westward and dominate the Gulf region during the 
upcoming weekend.

...CARIBBEAN SEA...

Convergent trade wind flow is supporting scattered showers and a
few thunderstorms over the far southwest Caribbean, from western
Panama to southeast Nicaragua. Dry stable low level air and 
generally fair weather prevails to the east of this area. Fresh
trade winds are evident off Colombia, south of Cabo Beata on the
south coast of Hispaniola, and in the Windward Passage. Gentle to
moderate trade winds persist elsewhere. Seas are 5 to 7 ft over
the south-central and southwest Caribbean, 4 to 6 ft in the
eastern Caribbean, and 2 to 4 ft over the northwest Caribbean. 

For the forecast, gentle to moderate trade winds are expected 
across the basin through Thu, except for moderate to locally 
fresh winds near the coast of Colombia, in the Gulf of Venezuela 
and Gulf of Honduras, and the south coast of Hispaniola. Winds 
will begin to increase across the E and central Caribbean tonight 
through Thu night, then persist through the weekend, as the 
Atlantic ridge builds westward. Strong to near gale force winds 
could be possible at night near the coast of Colombia and in the 
Gulf of Venezuela through Mon.

...ATLANTIC OCEAN...

The Atlantic ridge extends near the Azores to east-central 
Florida. Moderate NE to E winds are noted south of 25N and west of
35W, and over much of the eastern Atlantic east of 35W. Seas are 
4 to 6 ft in these areas. Lighter winds are noted elsewhere along 
the ridge axis mainly north of 25N and west of 35W with 3 to 5 ft 
seas in open waters.

For the forecast for the waters west of 65W, the Atlantic ridge 
will dominate the forecast waters while a surface trough will 
remain over or just off the coast of the SE of United States. 
Expect fresh to locally strong easterly winds late afternoon 
through the night just off the north of Hispaniola, including 
approaches to the Windward Passage, most of the forecast period. 

$$
Christensen